细颗粒态无机和有机含氮组分的形成、转化、传输和沉降在大气氮循环中发挥重要作用. 为了解上海亚微米颗粒物(PM$_{1}$)中含氮物质的质量浓度、组成及季节变化特征, 使用大流量采样器采集了 2017—2018 年 66 个 PM$_{1}$ 样品, 并应用离子色谱仪和紫外/可见光光度计分析了水溶性无机离子和水溶性有机氮(water-soluble organic nitrogen, WSON)的质量浓度. 结果表明: 上海 PM$_{1}$中NH$_{4}^{+}$-N、NO$_{3}^{-}$-N、WSON 的年平均质量浓度分别为 1.79、0.97、0.41 μg/m³; NH$_{4}^{+}$-N 对水溶性总氮(water-soluble total nitrogen, WSTN)的贡献最高(56%), NO$_{3}^{-}$-N 次之(31%), WSON 为 13%. 上海PM$_{1}$中含氮组分的质量浓度存在冬季最高、夏季最低的季节变化趋势, 但NH$_{4}^{+}$-N、NO$_{3}^{-}$-N 和 WSON 对 WSTN 贡献的季节变化存在明显的不同, NH$_{4}^{+}$-N 在不同季节变化较小, NO$_{3}^{-}$-N 表现出显著的冬高(38%)、夏低(18%)的特点, 而 WSON 夏季最高(22%)、冬季最低(8%). 正矩阵因子分解(positive matrix factorisation, PMF)法的源解析结果表明: 二次反应和生物质燃烧贡献了上海 PM$_{1}$ 中 WSON 的 48%, 燃煤贡献了 11%, 植物源挥发性有机化合物二次转化贡献了 20%, 餐饮和机动车贡献了 21%. WSON 的来源有显著的季节变化.

The formation, transformation, transportation, and deposition of inorganic and organic nitrogen within fine particles is critical in the nitrogen cycle. To understand the concentrations, compositions, and seasonal variations of the nitrogen-containing components within submicron particles (PM$_{1}$) in Shanghai, PM$_{1}$ samples were collected in Shanghai during 2017—2018 using a high-volume sampler. The concentrations of water-soluble ions and water-soluble organic nitrogen (WSON) were measured using ion chromatography and UV/Vis photometry. The annual average concentrations of NH$_{4}^{+}$-N, NO$_{3}^{-}$-N, and WSON within PM$_{1}$ in Shanghai were 1.79, 0.97, and 0.41 μg/m³ respectively. NH$_{4}^{+}$-N showed the highest contribution (56 %) to the water-soluble total nitrogen (WSTN), followed by NO$_{3}^{-}$-N (31 %), while the annual contribution of WSON to WSTN was 13 %. The concentrations of the nitrogen-containing components within PM$_{1}$ in Shanghai were highest in winter and lowest in summer. However, the contributions of NH$_{4}^{+}$-N, NO$_{3}^{-}$-N, and WSON to WSTN differed. The contribution of NH$_{4}^{+}$-N to WSTN showed a small seasonal variation, and a distinct trend of higher in winter (38 %) and lower in summer (18 %) was observed for the contribution of NO$_{3}^{-}$-N, while the contribution of WSON to WSTN was the highest in summer (22 %) and lowest in winter (8 %). Positive matrix factorisation (PMF) showed that secondary formation and the burning of biomass contributed 48 % of the WSON within PM$_{1}$ in Shanghai, with coal combustion contributing 11 %, secondary formation from biogenic volatile organic compounds 20 %, and emissions from kitchens and vehicles 21 %. The sources of WSON varied significantly according to season.